The best Tolkien cRPG I ever experienced was via a NWN persistant world. The people that made it understood Middle Earth down to the finest detail, and it showed in this mod.
Somebody also made a convincing Middle Earth mod for Age Of Wonders: Shadow Magic.
It seems the best Middle Earth stuff has been via fan-made mods of other games, the licensed stuff just doesn't seem to come off very well. I do want to check out LOTRO some day though.

-- You know the very powerful and the very stupid have one thing in common. They don't alter their views to fit the facts, they alter the facts to fit their views, which can be uncomfortable if you happen to be one of the facts that needs altering.